#!/usr/bin/python
# author Yu
# 2023年06月21日
import threading
import time


def say_hello1():
    for i in range(3):
        print('hello1')
        time.sleep(1)
def say_hello2():
    for i in range(3):
        print('hello2')
        time.sleep(1)

def say_hello3():
    for i in range(3):
        print('hello3')
        time.sleep(1)
if __name__ == '__main__':
    a=threading.Thread(target=say_hello1)
    b=threading.Thread(target=say_hello2)
    c=threading.Thread(target=say_hello3)
    a.start()
    b.start()
    c.start()
    a.join()
    b.join()
    c.join()